Health
Health calculators turn measurements — height, weight, age, activity level, dates — into standard estimates such as BMI, daily energy needs, body-fat percentage or pregnancy dates. They are useful for tracking trends and preparing questions for a professional, not for diagnosing anything.
Each tool applies a published formula with known limitations, so treat every result as a general information estimate.
Browse health calculators
Body composition
Energy & metabolism
Pregnancy & cycle
Training
Which health calculator do you need?
Start from a weight-for-height screen, or put that number in context with a healthy-weight range.
Estimate resting energy use at complete rest before adding activity.
Estimate daily calories for your activity level, or check how your usual intake compares.
Plan a calorie deficit and see how long a weight goal would take at that pace.
Split a daily calorie target into protein, carbohydrate and fat.
Estimate body-fat percentage from measurements rather than scale weight alone.
Estimate a due date and pregnancy progress from the last menstrual period, or an ovulation window for cycle planning.
Work out running pace, speed or the time a route should take.
Estimates, averages and ranges
Most health formulas were fitted to population averages. BMI, for instance, relates weight to height but does not distinguish muscle from fat, and energy equations such as Harris–Benedict estimate a typical person rather than measure you. Two people with identical inputs can legitimately have different real values.
That is why results are best read as a range or a trend: track changes over weeks, not the absolute number on a single day, and use the output to inform a conversation rather than to settle one.
Dates and cycle estimates
Pregnancy dating from the last menstrual period is a convention that assumes a regular cycle; an early ultrasound is the clinical reference. Ovulation estimates follow the same assumption, so they describe a likely window, not a confirmed event.
For training, pace calculators are arithmetic: distance divided by time. They summarize a session accurately but cannot account for terrain, heat or fatigue.
Important limitations
- These tools provide general information estimates and are not medical advice, diagnosis or treatment.
- Pregnancy, fertility and body-composition estimates assume typical conditions and are not a substitute for clinical testing.
- Significant weight changes, intense training plans and symptoms should be discussed with a qualified health professional.